Anyone have any experience-comments on UHS spinners. Looking to possibly get an 8-9" UHS for 72" IVO Med GA 582-C. Thanks !
Anyone have any experience-comments on UHS spinners. Looking to possibly get an 8-9" UHS for 72" IVO Med GA 582-C. Thanks !
Ty,
I have a UHS fiberglass spinner on our Kitfox. Painted to match the plane. It has worked out fine - no problems with balance, etc. They are balanced as a unit (Bulkhead and cone) at the factory as I understand it. Certainly easy to trim to length. A person should be careful not to overtorque the screws which hold the cone to the bulkhead- factory recommends using blue locktite on the screws.
Sincerely,
Dave S
KF 7 Trigear
912ULS Warp Drive
Do you have "in flight adjust"? I tried two "UHS 9P" spinners(one for 2 blade, one for 3 blade) on a medium with "in flight adjust" and while it worked in general there were problems with the back plate warping. The 9P is extra long to accommodate the adjustment motor so any change was really obvious as wobbling at the tip. The "back" plate goes forward of the adjustment motor(at least that was the design when I was going through this). As you torque the six prop bolts the fiberglass warped even with extra wide washers and threw the spinner off center. Did it work...? yes, but not ideal and could have been a problem down the line. I imagine a squash plate would help, but that meant more weight up front and even longer prop bolts. Perhaps the ground adjust version allows the back plate to be placed behind the hub effectively creating a squash plate effect. I ended up changing to a Kiev for moment of inertia and weight reasons anyways so don't know how the condition would contribute to longevity. It also kinda scared me that the IVO is pretty specific on torque and relies on the knurled plates to grip the blades. Throw some fiberglass into the sandwich and you could have some torque changes with compression. Maybe I was over worried, but food for thought.
Last edited by Geowitz; 02-11-2016 at 02:55 PM.
Ty,
I should have mentioned......on our S7 we have a ground adjustable warp drive prop and there is a 1/4" squash plate on top of the bulkhead. That may make a difference as Geowitz mentioned. I don't think the fender washers alone on top of the fiberglass bulkhead would be adequate. So our propshaft stack includes: Spacer, prop hub, bulkhead, squash plate, fender washers, AN washers, Bolts - this assembly has been stable.
Dave S
Thanks guys appreciate the info. UHS advised I use a 9p which does not seem right for the 582 72" Ivo 2 blade medium ground adjust with standard Ivo hub set-up. The 9p looks better suited for the IFA Ivo on a smooth cowl plane.
Ty
I had a problem with my UHS back plate. The fiberglass compressed each time I torqued the prop bolts and then loosened. This allowed the prop to operate below the specified torque, resulting in a crack in the prop blade from the bolt hole (two blade IVO). Since that time I'm running bare (well, no spinner anyway).
-- Paul S
Model III SN910
582 IVO Med
Hi Paul, Yikes !!! That does not sound good at all ! Years back I had the opportunity to chop up a spinner on my Lazair. Seems as though a hard working Dirt Dobber built a nest inside my spinner in the matter of week or two. The massive imbalance caused it to depart on the grôund during run up... thankfully. A large hunk of the spinner wacked me in the foot. No injury but Ow-weee did that hurt.
I think I'll look around for something else. My Lazair has custom spinner attachment plates turned from T-6 Billet. The spinners themselves are molded plastic that were made by the manufacturer of the Lazair. I've operated wîth them for a huge number of hours with no problems. I may need to think of something similar for the Kitfox. After hearing if your experience I think I'd rather go ugly than loose a blade. Thanks fôr the heads up.
Yeah, if I were to install one again I'd be looking for a metal back plate. Also, one with a good flange to support balace weights for dynamic balancing.
-- Paul S
Model III SN910
582 IVO Med
I am using the Whirlwind spinner and backplate (kind of spendy) which is carbon fiber. After 320 hours no loss of prop bolt torque at all.
Jim Ott
Portland, OR
Kitfox SS7 flying
Rotax 912ULS
Hi Jim, what prop are you using on your 912 ?
So far looks as though the simpliest way to cover up the ugly IVO GA adjuster and locknut would be with a Skullcap spinner. So far I've been unable to figure out exactly which one and from what source.